Each of the three studies is concerned with hip range of motion before and after surgery and its correlation to physical examination and patient satisfaction surveys.

Study 1: Total hip arthroplasty and total hip resurfacing

Two prospective, randomized, double-blind controlled trials were developed to compare total hip arthroplasty and total hip resurfacing, which are surgical procedures that can correct hip osteoarthritis. One study compares procedures between subjects with unilateral hip disease, and the other compares subjects with bilateral hip disease.

Total hip resurfacing is a bone-conserving alternative to standard total hip arthroplasty for treating young patients with hip osteoarthritis. The investigators have developed multiple protocols to characterize hip range of motion for each procedure and compare functional outcomes between the two procedures.

Currently, choosing one procedure versus another is based on the surgeon's personal preference. These studies were designed to address the major short-term, clinically important issues between the two types of procedures with special emphasis on functional outcome.

Study 2: Femoroacetabular impingement

The investigators developed a prospective clinical trial to compare active and passive hip range of motion before and after treatment for femoroacetabular impingement. This study will attempt to show objective differences in hip range of motion and confirm if these differences correlate with patient satisfaction and increased function reported in clinical questionnaires.

Femoroacetabular impingement occurs when there is abnormal contact between the femur and the acetabulum in the normal hip range of motion required for daily living activities or at extremes of motion.

The impingement can cause hip pain and lead to early osteoarthritis in young and active adults. The impingement is corrected with surgery, but very little is known about hip range of motion after surgical treatment.

Study 3: Preoperative and postoperative examinations

Common to the total hip arthroplasty-total hip resurfacing and femoroacetabular impingement studies is examination of the patient preoperatively and postoperatively (two or three months after surgery and one year after surgery). During these examinations, hip range of motion is measured passively and with motion analysis, and patients complete a set of questions that address hip function and patient satisfaction.

The unilateral and bilateral total hip arthroplasty and total hip resurfacing studies also involve strength testing of the hip muscles and hip X-rays.

Enrollment and data collection for these studies is complete. The investigators are analyzing the data and preparing to publish the results. The findings from this work will be valuable in guiding clinical practice.

Comparison of functional recovery for two surgical approaches for total hip arthroplasty

Researchers at Mayo Clinic are investigating two different minimally invasive surgical approaches for replacement of the hip.

Hip replacement surgery &mdash: total hip arthroplasty — is used for a broad range of patients and conditions. This technique poses a lower risk of muscle and tendon damage. This helps speed up recovery and reduces blood loss and pain, leading to shorter hospital stays.

Enrollment and data collection for this study is complete. The investigators are analyzing the data and preparing to publish the results.

Effectiveness of total knee arthroplasty and total hip arthroplasty

This study takes data collection outside of the lab setting to get a quantitative perspective on how total knee arthroscopy and total hip arthroscopy affect a patient's range of motion on a daily basis.

Total knee arthroplasty and total hip arthroplasty are effective at relieving pain and improving function. Standardized instruments have been developed to assess the severity of symptoms and evaluate the outcomes of treatment. A major component of these scoring systems is range of motion. This measure is widely used because it is an easily understood, direct measure of the joint's condition.

Also available are such new tools as body-fixed inertial sensors, including gyroscopes, accelerometers and magnetometers. With these tools, all the segments of the lower limb can be analyzed at the same time.

Unlike indoor standardized measurements, these ambulatory systems can be used anywhere in any condition, so it is now possible to collect objective and reliable 3-D data on joint motions required for activities of daily living from different samples of the population under real-life conditions.

Enrollment and data collection for this study is complete. The investigators are analyzing the data and preparing to publish the results.

Quantifying daily living activity levels in patients with total hip replacement

In this study, participants wear activity monitors on both their thighs and ankles in addition to their waists. The monitors are worn for four days (two weekend days and two weekdays) in their home environment to objectively assess the impact of hip arthritis (preoperative) and hip replacement (postoperative at two months, six months and one year) on physical activity.

Total hip arthroplasty is frequently used to treat severe osteoarthritis of the hip. The goal of the procedure is to improve quality of life for patients by decreasing pain and improving physical function.

Accelerometry-based activity monitoring provides a method to objectively measure actual performance of physical activity in everyday life and over an extended period in the patient's home setting, offering an outcome to measure that may provide novel insights into the effects of total hip arthroplasty on the patient's physical functioning.

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